Animal Blender
This plugin allows you to despawn animals quickly and easily. You select the type of animal you want to despawn and the radius you want it to take effect in and it will despawn all of those animals within the radius that do not have a name tag.
The command is /blend <animal> <radius>
For example, if you were to type in /blend sheep 50 then all sheep with no nametag would be despawned within a radius of 50 blocks.
This plugin currently allows you to despawn squid, sheep, cows, chickens and pigs.
GitHub repositry- https://github.com/davidg95/AnimalBlender